Smithsonian / USGS Weekly Volcanic Activity Report

The Weekly Volcanic Activity Report is a cooperative project between the Smithsonian's Global Volcanism Program and the US Geological Survey's Volcano Hazards Program. Updated by 2300 UTC every Wednesday, notices of volcanic activity posted on these pages are preliminary and subject to change as events are studied in more detail. This is not a comprehensive list of all of Earth's volcanoes erupting during the week, but rather a summary of activity at volcanoes that meet criteria discussed in detail in the "Criteria and Disclaimers" section. Carefully reviewed, detailed reports on various volcanoes are published monthly in the Bulletin of the Global Volcanism Network.

Based on satellite image observations, the Tokyo VAAC reported that a possible eruption at Chirinkotan on 26 July may have produced an ash plume that rose to an altitude of 4.6 km (15,000 ft) a.s.l. and drifted NW. A subsequent notice the next day stated that ash was observed in images and then dissipated.

AVO reported that during an overflight of Cleveland on 24 July a local field crew observed a thin layer of ash on the upper flanks (confirming a small explosion the week before) and vigorous steaming from the summit area. A small steam plume was recorded by the webcam on 27 July. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

The University of the West Indies (UWI) Seismic Research Centre (SRC) reported that seismic activity at Kick 'em Jenny had increased on 11 July. Another increase occurred on 23 July from 0125 to 0300, characterized by a "strong continuous signal." More than 400 micro and small earthquakes had been recorded since 11 July; the largest event was M 3.3. The Alert Level was raised to Orange (the second highest level on a 5-color scale) on 23 July.

At about 0200 on 24 July an hour-long explosion signal was recorded. Afterward, and through the next day, seismicity declined. The report encouraged mariners to observe an exclusion zone with a 5-km radius of the crater. Scientists observed nothing out of the ordinary at the surface above the volcano during an overflight on 25 July, and by 1800 no activity was recorded. On 26 July the Alert Level was lowered to Yellow.

Servicio Geológico Colombiano’s (SGC) Observatorio Vulcanológico and Sismológico de Manizales reported increased tremor at Nevado del Ruiz during the morning of 26 July. The webcam recorded an ash plume at 0830 that rose 3 km and drifted NW to SW; ashfall was reported in areas downwind including the municipalities of Chinchiná, Palestina, Santa Rosa de Cabal, Dosquebradas, and Pereira. Later than day seismicity decreased and the webcam showed gas-and-steam emissions that rose 300 m.

PVMBG reported that the eruption at Raung was ongoing during 16-23 July. Ash plumes rose 2 km and incandescence at the crater was visible. Seismicity fluctuated but remained elevated. The Alert Level remained at 3 (on a scale of 1-4), and the public was reminded not to approach the crater within a 3-km radius. Based on PVMBG information, and satellite-image and pilot observations, the Darwin VAAC reported that during 22-28 July ash multiple ash plumes from Raung rose to varying altitudes of 4.3-5.2 km (14,000-17,000 ft) a.s.l. and drifted as far as 400 km NW, W, SSW, S, and SSE. A news article from 29 July noted that 18 flights at most had been canceled during the previous few days due to the ash plumes, and that the Notohadinegoro Airport (2,100 km SW) had been temporarily closed.

JMA reported that during 21-24 July a small-scale, non-explosive event at Showa Crater (Aira Caldera’s Sakurajima volcano) was recorded, and incandescence from the crater was visible on 23 July. An explosion on 25 July ejected tephra as far as 800 m away. The Alert Level remained at 3 (on a 5-level scale).

On 22 July the Vanuatu Geohazards Observatory issued a statement reminding residents and visitors that Ambrym remained active; the Alert Level remained at 2 (on a scale of 0-5). Areas deemed hazardous were near and around the active vents (Benbow, Maben-Mbwelesu, Niri-Mbwelesu, and Mbwelesu), and in downwind areas prone to ashfall.

Based on analyses of satellite imagery and wind data, the Darwin VAAC reported that during 26-27 July ash plumes from Dukono rose to an altitude of 2.1 km (7,000 ft) a.s.l. and drifted 25-55 km NW, N, and NE.

Based on observations conducted at the Karangetang Volcano Observation Post in the village of Salili, PVMBG reported that white plumes rose as high as 200 m above the Main Crater and 25 m above Crater II during 15 and 19-22 July; foggy conditions prevented views during 13-14 and 16-18 July. Incandescence from the lava dome was observed at night. Incandescent avalanches from the fronts of 75-m-long lava flows traveled as far as 2.3 km E down the Batuawang and Kahetang drainages. Seismicity was dominated by signals characteristic of avalanches, with rare volcanic earthquakes. The Alert Level remained at 3 (on a scale of 1-4); visitors and residents were warned not to approach Karangetang within a 4-km radius.

KVERT reported that moderate activity at Karymsky likely continued during 17-24 July. Satellite images detected a thermal anomaly on 17 July as well as an ash cloud (8 km long and 5 km wide) that drifted 113 km E. Volcanologists observed multiple explosions during 21-22 July; ash plumes that rose as high as 2 km a.s.l. and drifted SE. The Aviation Color Code remained at Orange.

PVMBG reported that during 1 April-12 July white plumes from Kerinci rose 50-300 m and drifted E and W. Seismicity was dominated by signals indicating emissions (270 events per day on average) as well as shallow volcanic earthquakes (4 per day on average). The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were advised not to enter an area within 3 km of the summit.

HVO reported that seismicity beneath Kilauea's summit, upper East Rift Zone, and Southwest Rift Zone was at background levels during 15-22 July. The lava lake continued to circulate and spatter in the Overlook vent; occasional collapses of material briefly agitated the lake surface. Webcams recorded multiple incandescent outgassing vents within Pu'u 'O'o. The June 27th NE-trending lava flow continued to be active within 4-8 km NE of Pu'u 'O'o Crater.

PVMBG reported that during 1 June-12 July diffuse white plumes were observed rising 25 m above Anak Krakatau, although foggy weather often prevented observations. Seismicity fluctuated at a high level, and continued to be dominated by shallow and deep volcanic earthquakes. Signals indicating emissions were also recorded. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the volcano within 1 km of the crater.

PVMBG reported that during 15-22 July observers at the Lokon Observation Post in Kakaskasen Tomohon, North Sulawesi (4 km from the crater) reported that, although inclement weather sometimes obscured views of Lokon-Empung's Tompaluan Crater, white plumes were observed rising as high as 75 m above the crater. The number of volcanic earthquakes declined but still remained higher than levels recorded during 25 May-10 July. Signals indicating emissions were occasionally detected. The Alert Level remained at 3 (on a scale of 1-4). Residents and tourists were reminded not to approach Tompaluan Crater within a radius of 2.5 km.

PVMBG reported that during 1 June-13 July seismicity at Papandayan was dominated by shallow volcanic earthquakes but also consisted of deep volcanic earthquakes, low-frequency earthquakes, harmonic tremor, and hybrid events. Visual monitoring occurred from the Pakuwon Village post; where observers noted white plumes rising at most 30 m above the crater. The Alert Level remained at 2 (on a scale of 1-4); residents and tourists were reminded not to approach the craters within a 1-km radius.

CENAPRED reported that during 22-28 July the seismic network at Popocatépetl recorded 34-102 daily emissions consisting of water vapor, gas, and sometimes ash; cloud cover often prevented visual observations. Variable nighttime crater incandescence was observed, and explosions were detected almost daily. Gas-and-ash plumes rose 1.5 km on 26 July, and two explosions on 27 July produced ash plumes that rose less than 1 km. The Alert Level remained at Yellow, Phase Two.

PVMBG reported that both white plumes and gray to brownish-gray plumes from Semeru were observed rising as high as 600 m above the crater and drifting N, NW, W, and SW during 1 April-13 July; inclement weather sometimes prevented observations. Ashfall was reported in Sawur and surrounding areas in April, and incandescent avalanches that traveled as far as 1 km were observed in May. Seismicity was dominated by explosions and emission signals. The Alert Level remained at 2 (on a scale from 1-4); visitors and residents were warned to avoid the SE flank within 4 km of the crater.

AVO reported that seismicity at Shishaldin continued to be elevated over background levels 22-28 July, indicating that low-level eruptive activity confined to the summit crater likely continued. Cloud cover prevented satellite and webcam observations. The Aviation Color Code remained at Orange and the Volcano Alert Level remained at Watch.

Based on satellite images, webcam views, weather models, and information from PVMBG, the Darwin VAAC reported that on 23 July an explosion at Sinabung generated an ash plume that rose to an altitude of 7 km (23,000 ft) a.s.l. and drifted 25-55 km W. An explosion on 26 July generated an ash plume that rose to an altitude of 3.7 km (12,000 ft) a.s.l. and drifted E.

PVMBG reported that during 1 March-13 July white plumes from Tengger Caldera's Bromo cone rose as high as 100 m above the crater, and a sulfur dioxide odor was periodically noted at the Bromo observation post. Seismicity was dominated by tremor, but also included volcanic earthquakes. The Alert Level remained at 2 (on a scale of 1-4). Residents and visitors were warned not to approach the crater within a radius of 1 km.

Instituto Geofísico del Perú (IGP) Observatorio Volcanológico del Sur (OVS) reported that during 21-26 July seismic activity at Ubinas increased, particularly during 25-26 July. Constant gas, steam, and ash emissions were observed during 21-24 July. On 25 July bluish gas emissions were observed most of the day until a strong explosion (the strongest so far in 2015) at 1903 ejected ash, lapilli, and ballistics. Lapilli and some 1-2-cm-long fragments fell in the towns of Ubinas (6.5 km SSE) and Escacha. Another explosion was registered at 2003.

The RSS (Really Simple Syndication) feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website.

The CAP (Common Alerting Protocol) feeds are XML files specifically formatted for disaster management. They are similar in content to the RSS feed, but contain no active links.

A Google Earth network link for the Weekly Volcanic Activity Report can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.

Criteria & Disclaimers

Criteria

The Weekly Volcanic Activity Report does not necessarily include all volcanic activity that occurred on Earth during the week. More than a dozen volcanoes globally have displayed more-or-less continuous eruptive activity for decades or longer, and such routine activity is typically not reported here. Moreover, Earth's sea-floor volcanism is seldom reported even though in theory it represents the single most prolific source of erupted material. The Weekly Volcanic Activity Report summarizes volcanic activity that meets one or more of the following criteria:

- A volcano observatory raises or lowers the alert level at the volcano.
- A volcanic ash advisory has been released by a volcanic ash advisory center (VAAC) stating that an ash cloud has been produced from the volcano.
- A verifiable news report of new activity or a change in activity at the volcano has been issued.
- Observers have reported a significant change in volcanic activity. Such activity can include, but is not restricted to, pyroclastic flows, lahars, lava flows, dome collapse, or increased unrest.

Volcanoes are included in the "New Activity/Unrest" section of the Weekly Volcanic Activity Report if the activity occurs after at least 3 months of quiescence. Once a volcano is included in the "New Activity/Unrest" section, updates will remain in that section unless the activity continues for more than 1 month without escalating, after which time updates will be listed in the "Continuing Activity" section. Volcanoes are also included in the "New Activity/Unrest" section if the volcano is undergoing a period of relatively high unrest, or increasing unrest. This is commonly equal to Alert Level Orange on a scale of Green, Yellow, Orange, Red, where Red is the highest alert. Or alert level 3 on a scale of 1-4 or 1-5.

It is important to note that volcanic activity meeting one or more of these criteria may occur during the week, but may not be included in the Weekly Volcanic Activity Report because we did not receive a report.

Disclaimers

1. The Weekly Volcanic Activity Report is intended to provide timely information about global volcanism on a weekly basis. Consequently, the report is generated rapidly by summarizing volcanic reports from various sources, with little time for fact checking. The accuracy of the Weekly Volcanic Activity Report is dependent upon the quality of the volcanic activity reports we receive. Reports published in the Bulletin of the Global Volcanism Network are monthly, and more carefully reviewed, although all of the volcanoes discussed in the Weekly Volcanic Activity Report are not necessarily reported in the Bulletin. Because of our emphasis on rapid reporting on the web we have avoided diacritical marks. Reports are updated on the Weekly Volcanic Activity Report web page as they are received, therefore information may be included regarding events that occurred before the current report period.

2. Rapidly developing events lead to coverage that is often fragmentary. Volcanoes, their eruptions, and their plumes and associated atmospheric effects are complex phenomena that may require months to years of data analysis in order to create a comprehensive summary and interpretation of events.

3. Preliminary accounts sometimes contain exaggerations and "false alarms," and accordingly, this report may include some events ultimately found to be erroneous or misleading.

4. Many news agencies do not archive the articles they post on the Internet, and therefore the links to some sources may not be active. To obtain information about the cited articles that are no longer available on the Internet contact the source.

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Information presented on this website is considered public information and may be distributed or copied. Use of appropriate byline/photo/image credit is requested. We strongly recommend that USGS data be acquired directly from a USGS server and not through other sources that may change the data in some way. While USGS makes every effort to provide accurate and complete information, various data such as names, telephone numbers, etc. may change prior to updating. USGS welcomes suggestions on how to improve our home page and correct errors. USGS provides no warranty, expressed or implied, as to the accuracy, reliability or completeness of furnished data.

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An RSS (Really Simple Syndication) feed for the Weekly Volcanic Activity Report first made available on 5 March 2008 can be utilized with the aid of various free downloadable readers. The report content of the news feed is identical to the Weekly Volcanic Activity Report minus some features including the header information (latitude and longitude and summit elevation), the Geologic Summary, and a link to the volcano's page from the Global Volcanism Program. Each volcano report includes a link from the volcano's name back to the more complete information in the Weekly Volcanic Activity Report on the Smithsonian website. On 12 March 2009, GeoRSS tags were added so that the latitude and longitude for each volcano could be included with the feed.

At the end of each individual report is a list of the sources used. We would like to emphasize that the World Organization of Volcano Observatories (WOVO) website (http://www.wovo.org/) lists the regional volcano observatories that have the most authoritative data for many of these events.

A Google Earth network link for the Weekly Volcanic Activity Report was first made available on 1 April 2009. This file can be loaded into the free Google Earth software, and in turn will load placemarks for volcanoes in the current weekly report. Placemark balloons include the volcano name, report date, report text, sources, and links back to the GVP volcano page for that volcano and to the complete Weekly Report for that week.